How to install your Bubble Windows
1. Place the exterior frame against the body and trace the perimeter of the window that makes contact with the body. This does not need to be a laser precise cut. the window has 5/8” flanges which means you have almost a 1/4" of play around the window and you may need that wiggle room when trying to line it up with the inner frame later. Shoot for a decent cut but be aware that you will probably have to open this hole up some. There are welds on the inner frame that sometimes interfere. Try not to grind the welds down. Rather make room for them to slip in to the body by grinding or filing on the body. I sometimes use a carbide burr or roll sander to open the corners up. I like to cut out enough room with a cut off wheel that I can fit my electric shears in and cut out the shape. An angle grinder is ok. Reciprocating saw with a fine tooth blade for sheet metal. Maybe 12-18 TPI. If you use a grinder, torch, plasma cutter etc. of course be aware of where you are throwing sparks. Grinders can embed metal in to glass an aluminum. Of course clear all work areas of flammables. Wear safety glasses and other appropriate protection.
4. Use 5/8” long #8 screws to join the frames together. If your wall gap is larger than 2” you will have to use longer screws and then create a barrier to close the wall gap decoratively. As long as the interior frame is pulling on the exterior you’ll get a good tight install against the body. When you’ve made it through fitment you can now seal the window against the body. If you want to be able to remove the window silicone might be a good sealant. It does eventually dry out and need to be removed and resealed. Butyl rope like 3M’s window weld in 1⁄4” diameter is a more permanent option. This can be squished around the perimeter flange to mate the window to the body. Butyl never dries and more can be pushed in using a plastic squeegee if you need to fill a gap. It does however leave a mess on the body and can be a strong adhesive sealing the window against the van making later removal difficult.